1. Technical Field
The invention includes embodiments that relate to the field of radiation detectors. Embodiments may include a scintillator composition for use in a radiation detector. Embodiments may include a method of making and/or using the scintillator composition.
2. Discussion of Related Art
Radiation detectors may detect gamma-rays, X-rays, cosmic rays, and particles characterized by an energy level of greater than about 1 keV. Scintillator crystals may be used in such detectors. In these detectors, a scintillator crystal may be coupled with a light-detector, such as a photodetector. When a photon from a radionuclide source impacts the crystal the crystal may emit light in response. The light detector may detect the light emission. In response, the photodetector may produce an electrical signal. The electrical signal may be proportional to the number of light emissions received, and further may be proportional to the light emission intensity. A scintillator crystal may be used in medical imaging equipment, e.g., a positron emission tomography (PET) device; as a well-logging tool for the oil and gas industry; and in other digital imaging applications.
Medical imaging equipment, such as positron emission tomography (PET), may employ a scintillator crystal detector having a plurality of pixels arranged in a circular array. Each pixel may include a scintillator crystal cell coupled to a photomultiplier tube. In PET, a chemical tracer compound having a desired biological activity or affinity for a particular organ may be labeled with a radioactive isotope. The isotope may decay by emitting a positron. The emitted positron may interact with an electron, and may provide two 511 keV photons (gamma rays). The two photons are emitted simultaneously and travel in almost exactly opposite directions, penetrate the surrounding tissue, exit the patient's body, and are absorbed and recorded by the detector. By measuring the slight difference in arrival times of the two photons at the two points in the detector, the position of the positron emission inside the target can be calculated. Naturally, the positron emission coincides with the position of the isotope, and of the tissue or organ labeled by the isotope. A limitation of this time difference measurement may include the stopping power, light output, and decay time of the scintillator composition.
Another application for a scintillator composition is in a well-logging tool. The detector in this case captures radiation from a geological formation, and converts the captured radiation into a detectable light emission. A photomultiplier tube may detect the emitted light. The light emissions may transform into electrical impulses. The scintillator composition, and associated hardware, must function at high temperature, as well as under harsh shock and vibration conditions. A nuclear imaging device may encounter high temperature and high radiation levels.
It may be desirable to have a scintillator composition and an article employing a scintillator composition that has one or more properties and characteristics that differ from those currently available. It may be desirable to have a method of making and/or using a scintillator composition that may differ from those currently available.